Chmielewski et al. [4] investigated the effect of additives, such as water, ammonia, and alcohol, on the removal efficiency of NOx with and without SO2 in the electron beam flue gas treatment process (EBFGT). When no additive was used, the removal efficiency of NOx at initial concentration (500–600) ppm was 40% at 10.9 kGy of absorbed dose. It was confirmed that when alcohol was added, the denitrification efficiency increased by 20%. However, in the case of using humidity and ammonia, the removal efficiency was increased by less than 10%. Also, it was found that water content strongly influenced SO2 removal.He also found that when a high concentration of NO is treated, some O or O3 back reactions (reduction reactions) occur, as follow: